Pressure vests suspected in F-22 pilot problems

WASHINGTON - A potentially faulty pressure vest is the latest clue in a yearlong mystery over why Air Force pilots flying Lockheed Martin's F-22 Raptor keep getting dizzy and disoriented.

Pilots have been instructed to stop using the vest for routine flight operations as Air Force officials work on a fix, the service's Air Combat Command reported. The vest, part of a "G-suit" used to help pilots avoid blacking out during high-speed maneuvers, "increases the difficulty of pilot breathing under certain circumstances," according to an emailed statement.

In response to a Review-Journal query, an Air Combat Command spokesman, Lt. Col. Edward "Tadd" Sholtis, said the equipment in question is the CSU-17/P pressure vest.

"It is made by a company called Sewing Technologies," Sholtis wrote in an email Thursday.

"Gentex Corporation makes the hose and the valve on the vest, which control its inflation and deflation," he wrote, noting the pressure vest is worn on the pilot's upper body and is separate from the anti-G force garment known in aviation circles as a "G-suit."

That life-support garment is worn around a pilot's legs and abdomen and contains bladders that inflate to prevent blood from pooling during acceleration from turns and rapid maneuvers when pilots experience high gravitational forces.

"We're researching the history of the vest," said Sholtis, who didn't have specifics on its history of ground tests.

Unable to explain episodes of dizziness, Air Force officials are looking at everything from hoses, masks and G-suits to top-secret coatings and adhesives used in the plane's radar-absorbing stealth skin that makes it harder to track. Engineers and investigators have come up short of a solution to symptoms that include what is called a "Raptor cough."

About two dozen pilots and five ground maintenance workers have reported symptoms associated with a lack of oxygen. There have been 11 reported incidents since the plane resumed flying operations last year after a four-month halt because of safety concerns.

The Pentagon has spent $67 billion buying 188 of the supersonic jets, which have never flown in combat. It plans to spend $11.7 billion to upgrade the planes .

In all, 15 Raptors are assigned to Nellis Air Force Base in the north Las Vegas Valley. They are flown by the 422nd Test and Evaluation Squadron and the 433rd Weapons Squadron.

Review-Journal writer Keith Rogers contributed to this report.